Accurate tritium transport properties of prospective tritium permeation barriers(TPBs)are essential to design practical tritium systems for fusion reactors.By passing a temperature and rate controlled sweep-gas over specimen surface to carry the permeated tritium to an ion chamber,gas-driven permeations of tritium have been performed on containers of type 321 stainless steel with Al2O3/FeAl barrier,to determine T-permeation reduction performance and mechanism of the barrier.